Oil Column Method for Magnetic Microspheres with Core-shell Structure

摘要

Spherical alumina catalysts have been widely used in fluidized bed and slurry-bed or catalyst carrier due to their excellent pore structure, large surface area, good physical strength and resistance to acids and stability. Magnetic microspheres of γ-Fe_2O_3 @ Al_2O_3 with core-shell structure were obtained by γ-Fe_2O_3 magnetic core coating with aluminum sol. After aging, drying and calcinations process, microspheres with certain hardness and magnetic properties can be obtained. During the preparation of core-shell structure microspheres, effect of both the content of aluminum sol, hexamethylenetetramine(HMT), magnetic core γ-Fe_2O_3 and process parameters of shaping time, aging temperature, calcination temperature on the properties of the spherical carrier was investigated. The optimum properties of microsphere carrier for hardness of 36.32 N/mm, specific surface area of 89.016 m /g, pore volume of 0.874 cm~3/g and average pore diameter 18.51 nm were synthesized, respectively.